Renewable energy for providing grid support

In the Allfred project, the researchers are investigating the extent to which renewable energy generation systems are suitable for providing grid support.
Image: SMA Solar Technology AG

In the Allfred project (Innovative all-round FRT test system to ensure grid stability), the project participants would like to find out whether the grid support provided by renewable energy generation systems can be verified more precisely using extended tests. The tests are examining wind turbines as well as solar inverters and generator sets such as used, for example, in combined heat and power plants.

This is necessary because previously existing and commercially available systems can only be used viably within certain limits. For example, they can only be used to generate voltage dips, and this only works to a very limited extent with overvoltages. With Allfred, on the other hand, it should be possible for the first time to test various effects using just one system. Some examples include:

Reproducible switching moments

Detection of overvoltages during faults

Different grid impedances

Different voltage vector groups

Vector surges in the entire voltage system

Right at the start of the project the developers have constructed a 10-kW test model and tested it on a consumer load, string inverter and a small CHP with success. Based on these tests, the test system will be further optimised in terms of details such as the transformer design.